Hydraulic tool control unit



June 21, 1949. A. P WATERSON 2,474,134

HYDRAULIC TOOL CONTROL UNIT Filed April 24, 1947 3 Sheets-Sheet-l INVENTOR.

ARTHUR RWATERSON arramvtr.

June 21, 1949. v I A. P. WATERSON 2,474,134

HYDRAULIC TOOL. common nun A TTORNEYS.

Patented June 21, 1949 HYDRAULIC TOOL CONTROL UNIT Arthur P. Waterson, Tulsa, Okla., assignor to The R. K. LeBlond Machine Tool Company, Cincinnati, Ohio, a corporation of Delaware Application April 24,1947, Serial No. 743,669

(Cl. 12l41) 3 Claims. 1

This invention pertains to an improved hydraulic actuating device for a tool carrier. More particularly, this invention is directed to a duplicating attachment for actuating the cutting tool of a machine tool. a

One of the objects of this invention is'to provide a duplicating attachment in which the actuating member for the tool slide, the tracer control valve, and the stylus are all contained in the same tool carrying device.

Still another object of this invention is to provide a duplicating attachment for lathe in which the actuating member, the control member, and the template actuated stylus are all mounted on the same tool carrying slide.

Still another object of this invention is to provide, in a hydraulic duplicating attachmentfor lathe, an arrangement which may be readily substituted for the compound rest and which is self-. contained in that the hydraulic actuating cylinder, the servo control valve, and the stylus for actuating said valve are all contained in and carried on the tool slide actuated by operation of the tracer valve stylus.

Still another object of this invention is to provide, in a hydraulic duplicating attachment, a servo valve including a novel method of applying fluid pressure to the movable member of said valve from a fixed supply positioned on the tool slide of the attachment.

A still further object of this invention is to provide a duplicating attachment for lathe having a main tool slide casting which contains toolsupport, the hydraulic actuating cylinder, and the tracer valve, in an integral close-coupled unit.

Still another object of this invention is to provide a hydraulically actuated duplicating attachment for lathe in which a fluid pressure cylinder is utilized to actuate the tool slide and is carried in said slide, together with a tracer controlled valve for said cylinder mounted'in but off to one side of said cylinder in the tool slide member.

Still another object of this invention is to provide an improved duplicating attachment for lathe in which the fluid pressure supply between the tracer controlled valve and the operating cylinder for the attachment is eifected through rigid conduits having a minimum length and volumetric content.

Further features and advantages of this invention will appear from a detailed description of the drawings in which:

Figure 1 is a side elevation of a duplicating attachment incorporating the features of applicants invention.

Figure 2 is a plan view of the attachment shown in Figure 1,,

Figure 3 is a fragmentary view indicated by the line 3-3 in Figures 1 and '7.

Figure 4 is a section on the line 4-4 of Figures 1 and 2.

Figure 5 is an end view of the attachment on the line 5-5 of Figures 1 and 2.

Figure 6 is a. diagrammatic section on the line 6-6 of Figure 5, particularly showing the hydraulic operating and control circuit.

Figure '7 is an enlarged sectional view on the line 1-1 of Figure 5.

Figure 8 is an enlarged section through the servo valve, particularly showing the control ports indicated by the line 8-8 in Figure 2.

Figure 9 is an isometric perspective view of one of the port forming collars of the control valve.

The duplicating attachment comprises a base member which may take the form of a swivel slide bottom H] which may be attached to the tool carrier or cross slide of the lathe in place of the usual compound rest utilizing the same clamping and swivel mounting of well known character. 0n the swivel slide member is formeda pair of dovetailed guide surfaces I I, Figure 5, upon which is reciprocatably mounted the tool carrier or tool slide l2 which is preferably provided with the usual T slot I3 in which may be placed the usual lathe tool post, wedge, and clamping screw mechanism of well known character.

The tool slide I2 is reciprocated on the swivel base member N] by means ofa fluid pressure cylinder mounted rigidly to the tool slide i2 and which may take the form of a cylinder I l having cylinder heads l5 and I6 engaging the ends of the cylinder in fluid tight connection by mean of suitable. packing [1. The head I6 is provided with a suitable diameter l8 nicely fitting in a bore I 9 formed in the tool slide I2 and having an abutment surface 20 engaging a mating surface 21 of the tool slide 12. Through the head i5 passes a series of clamping bolts 22 which are threaded into the tool slide 12 and, when drawn up tightly, force the head l6 up against the surface 2! to securely hold the tube l4 between both of the heads l5 and it through the gaskets H to form a fluid tight actuating cylinder. The cylinder is supported at its outer end in a bore at the point 23 in the tool slide l2.

, In the cylinder id is a piston 24 to which is connected the piston rod 25 passing through a suitable packing gland 26 in the cylinder head l6, the outer end of the piston rod being connected by the screw 21 to a bracket 28 secured to the swivel base I by suitable screws 29 and pins 30a so that when fluid pressure is applied in the chamber 36 of the cylinder, forward movement will be effected in the tool slide l2 and when pressure is applied in the rear chamber 3! of the cylinder behind the piston 24 a return movement will be effected in the tool slide i2.

Formed integral with the tool slide I2 is the servo valve housing He in which is carried the servo control valve for the fluid pressure cylinder comprising a valve spindie 32 having a flanged abutment surface 33 against which the series of port forming collars 34, 35, 38, 31, and 3B are firmly secured by the collar 39 when the lock nut 40, threaded on the end of the spindle 32, is tightened down to thereby hold the spindle 32 securely to the valve chamber cover cap ii when the screws 62 are appropriately locked in place. A softpacking washer d3 engaging the outer face 44 of the flange portion 33 of the spindle 32 engages the inner face 45 of the valvebody portion i2a to prevent leakage of discharge fluid out past the space 56 between the spindle 32 and the housing I2a. Between the collars 3t and and 31 and 38 are formed the exhaust ports 41 and 4B which communicate with annular grooves 49 and 50, respectively, formed in the spindle 32 which in turn communicate with radial passag ways 5! and 52 extending inwardly and communicating with the cylinder chamber passageways53 and 54. The chamber 53 is connected through a suitable rigid conduit 55 to the chamber 30 oi the cylinder id while the passageway 54 is connected through the rigid conduit 56 to the chamber SI of the cylinder It. It is to be understood, however, that drilled passageways formed directly in the valve housing portion l2a and tool slide l2 may be utilized to intercommunicate fluid pressure from the passageways 53 and 54 to the respective chambers 30 and 3| in the cylinder i4. Intake ports 5'! and 58 between the collars 3B and 36 and 36 and 31 communicate with annular grooves 59 and 66 which in turn communicate through the radial passageways 6i and 62 with the passageways 53 and 54.

In this way. relatively short rigid fluid conducting passageways of small volumetric con tent are provided from the control valve stem 32 to the cyl nder chambers to thereby nullify the efiect of flexible conduits and the resiliency of lon columns of hydraulic fluid and the incident flexibility and resiliency present therein which results in the nicety and accuracy 01' control possible with applicant's arrangement.

Sliding on the outer diameter portion of the collars 34 through 38. inclusive. are the mating port forming collars 63. 54, S5. B6, and 67 which are held against the abutment surface 68 of the valve sleeve 69 by the lock nut 73. the entire assembly. includin the ;s eeve 69 being thus reciprocatable axiallyon the collars 36 through 38 held on the spindle 32. Exhaust ports TI and 12 are formed between the respective collars 63 and 6E and 66 and 67 which communicate with annular grooves i3 and it which in turn exhaust through radial openings 75 and it formed in the valve sleeve 69 into the discharge or return chamber 77 formed in the portion lie of the tool slide l2. The pressure supply ports 18 and .79 formed between the collars 5t and 65 and $5 and 66 communicate with the passageways 8t] and ti in the valve sleeve 39 which open into a bore 82 In this bore 82 is nicely slidably mounted the 7 pressure supply plunger 83 having a recessed an- 5 nular groove 84 communicating through radial openings 85 with its axial passageway 86. The member 83 has a flanged end portion 81 against which a lock nut 88 carried in the cover plate 4| is tightened to rigidly secure the member 83 to this plate so that the valve sleeve 69 may slide relative to member 83 asa sliding movable fluid connection to at all times provide fluid pressure in the passageway 86 for the pressure supply ports 18 and 19 of the valve.

The pressure supply may be obtained from a suitable fluid pressure pump 88 receiving a supply through the suction line 80 from a fluid pressure reservoir 9i and delivering pressure through the line 62 to the passageway 86. A suitable pressure relief valve 93 connected through a line 98 to the pressure supply line 92 and discharging through a line 95 to the fluid reservoir 3| may be utilized to regulate the maximum predetermined desired pressure supplied in the line t2 and to the control valve. Discharge from the chamber 11 is received out through the discharge or exhaust opening 96 and the line 91 for return to the fluid reservoir 9!.

Referring particularly to Figure 8, there is shown a specific series of dimensions for the collars 35, 38, 31. and the mating collars 64, 65, and 66 as showing one preferred form of embmiiment of the control servo valve for the hydraulically operated duplicating attachment. While this specific illustration serves to show a preferred arrangement, it is understood that applicant is not limited in the exact dimensions there shown but utilizes this illustration as a means for explaining the particular operation of the control valve porting system. With the particular dimensions of the parts 35, 36, and 3! and 64, 65, and 66 as shown in Figure 8, the openings between the respective ports 4812, 58-49, 51-48, and 471l when the valve is in neutral or intermediate position of nonmovement of the tool slide and cylinder M with respect to the piston 26 are respectively, one-thousandth, twothousandths, two-thousandths, and one-them sandth of an inch, as marked on the drawing. The ports recited and the spacing dimensions indicated are formed by abutment surfaces 98 formed on the respective collars associated with the valve such as shown, for example, on the collar 66 in Figure 9 so as to provide a maximum flow of fluid around the entire diameter of the respective collars so that the minutest of movements of the valve sleeve 69 effects a rapid and major change in the flow of fluid between the respective ports. go With the valve sleeve 69 moved to the left from neutral position, Figure 8, a distance of travel one-thousandth of an inch will substantially close the intercommunication between the ports 81 and i I, so as to prevent rapid discharge of fluid from the chamber 30 of the cylinder while opening the orifice between the ports 51 and 18 a greater amount to increase the flow of fluid into this chamber 30. At the same time, the pressure input orifice between the ports 58 and 79 will be closed down to one-thousandth of an inch while the exhaust discharge from the cylinder chamber 3| will be opened to two-thousandths between the ports 68 and 72. As a result, pressure will increase in the chamber 30 and the flow will increase therein while discharge will be more rapid and pressure reduced'in the chamber 3! with the result that the tool slide I2 will be fed toward the work. The opposite condition prevails when the valve sleeve 69 is moved in the opposite direction fromneutral in which case greater pressure and supply will be applied in the chamber 3I while greater escape and lower pressure will be applied in the chamber 30 for retracting the tool slide.

Thus, by regulating the position of the valve sleeve. 69, the tool slide can be automatically caused to follow any manipulation of the valve sleeve 69 in either direction or to maintain itself in a fixed position when the valve is held normally in a neutral position of balanced pressures in the chambers 30 and 3|. It is to be noted that in the operation of the valve at all times is fluid flow taking place in through the supply ports I8 and I9 and discharging out through the exhaust ports H and I2 under any operating conditions even though these conditions vary greatly, depending upon the direction of movement of the valve so as to in this way maintain proper pressure supply and make up for leakage in any part of the hydraulic system between the control valve and the hydraulic cylinder and thereby always maintain an exact and positive control of the relative position of the cylinder and piston and the tool slide with respect to a work piece in the machine.

The valve sleeve 69 may be actuated in automatic duplicating or tracer control operation during the movement of the tool carrier upon which the attachment is mounted by means of a tracer finger 99 or stylus arm pivotally mounted on a suitable pin HID-carried in the bracket I! attached to the cap M of the attachment by suitable screws I02. The upper portion of the stylus arm 99 engages a pin I03 carried in a suitable guide bushing I04 to engage the surface I05 of the valve sleeve 69 while, in the other end of the arm 99 is provided a stop screw I06 engaging against the surface I01 of the cover plate 4] to limit its outward counterclockwise swinging movement as shown in Figures 1, 7, and 8. A suitable stylus contact tip 99a engages a template I08 which is arranged to move relatively to the tip 99a-during the machining operation to thereby actuate the arm 99 and the valve sleeve 69. A suitable bias spring I09 supported on a pin IIO carried in the housing portion Ho and abutting against the surface III of the valve sleeve 69 serves to normally move the valve sleeve when the tracer tip is released from the template in a position to automatically effect forward infeeding movement of the tool slide I2 toward the work for initially bringing the tracer tip into contact with the work template I08. Movement ofthe control valve in the opposite direction is limited by a stop screw H2 threaded at H3 in the housing 12a and locked in place by a lock nut IHI and abutting surface III serves to position the valve so it will never be moved so far as to completely close 01f the pressure supply orifice formed between the ports 51 and I8 and render the device inoperative.

As a result of this unique design there is provided'extremely high sensitivity with a minimum of movement of'the valve sleeve 69 and the tracer finger arm 99 resulting in a highly accurate and responsive duplicating tracer controlled tool slide for a machine tool or the like.

While the apparatus herein disclosed and described constitutes a preferred form of the invention, it is to be understood that the apparatus is capable of mechanical alteration without departing from the spirit of the invention and that such mechanical arrangements and commercial adaptations as fall within the scope of the appendant claims are intended to be included herein.

Having thus fully set forthand described this invention, what is claimed as new and desired to be secured by United States Letters Patent is:

1. In a fluid pressure operated tool slide, a control valve, comprising a valve spindle fixed in said tool slide, a series of collars fixed on said spindle, a member relatively movable to said spindle including cooperating collars fixe'd on said member and movable on said first mentioned series of collars to form intake and exhaust ports, a fluid pressure actuating cylinder on said tool slide and rigid conduit means interconnectin said valve with said cylinder, a source of fluid pressure connected to an inlet port for said valve fixed on said tool slide, and a slidingmovable fluid connection between said inlet port and said movable valve member.

2. In a hydraulic control valve having a valve spindle, a series of port forming collars fixed on said spindle, a fluid pressure cylinder controlled by said valve, rigid fluid passageways between said spindle and said cylinder, a movable valve sleeve having a series of port forming collars operatively related to said first mentioned port forming collars on said spindle, and means for reciprocating said movable valve sleeve by a template.

3. In a hydraulic control valve having a valve spindle, a series of port forming collars fixed on said spindle,-a fluid pressure cylinder controlled by said valve, rigid fluid passageways between said spindle and said cylinder, a movable valve sleeve'having a series of port forming collars operatively related to said first mentioned port forming collars on said spindle, and means for reciprocating said movable valve sleeve, a source of fluid pressure and means including a sliding movable fluid pressure connection for applying said fiuid to said movable member and ports formed by the port forming collars therein.

' ARTHUR P. WATERSON.

REFERENCES CITED The following referenlces are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,016,167 McCulloch Jan. 30, 1912 1,642,193 Banning Sept. 13, 1927 2,016,931 Richard Oct. 9 2,101,712 Johansen Dec. 7, 1937 2,437,570 Von Zelewsky Mar. 9, 1948 

